Postby MacFangus » 14 Feb 2017, 13:45
Okay, so my 2550 started in with a nasty 60Hz hum this afternoon. I had been meaning to replace the 30 year old filter caps with new ARS caps, which I did do. I have the new caps installed, but it still suffers from the same issues. When I plug/unplug the guitar cord, I get a whistling sound at the halfway point. I've never experienced this before with any amp. Doesn't matter if the other end is plugged into the guitar, or not... I still get the whistling. Anyone else experience this? Any ideas what is going on? I cleaned the input with Deoxit, and also changed the preamp tubes... Neither efforts helped. I also tried using different guitar cords.